There shouldn't be any problem with a 12 minute clip. If you shot non-stop for half an hour, which you can't do with the camera, the sound could be a frame or two off by the end. For normal production there shouldn't be an issue. You could do a tail slate with the clapboard as well as a head slate for an easy check when you drop it into your timeline. Or, if you always make sure the camera mic is on for reference audio, no real need for a clapboard, just any sharp sound would do for easy synching.

Brian, I don't think you have to worry about giving that place free publicity--they're $100 over B&H's price on the Tascam and about $50 over on the Zoom.